Display size on mobile devices, such as smart phones, personal digital assistants, etc., is a key design parameter. In particular, some designs seek to maximize the size of the display relative to the overall device footprint (i.e., minimize the non-viewable area around the display). This requires a reduction in the width of the side borders of the device. One consequence of side border reduction, however, is weakening of the connection between the device housing and the display assembly structure, which includes an outer glass lens adhered to the housing and bonded to an organic light-emitting diode (“OLED”) display using liquid optically-clear adhesive (“LOCA”). Normally, the lens to housing adhesive around the borders of the lens carries most of the mechanical shock forces imparted to the display assembly when the device is dropped. If the side border area is reduced, then the area of adhesive used between the lens and the housing may also be reduced, resulting in an unacceptably weak mechanical connection between the housing and the display assembly.
One option for strengthening the mechanical connection is to add adhesive directly between the OLED display and another structural component of the device disposed below the OLED display. This, however, requires the display to carry forces imparted to the device when dropped. In particular, the shock forces would be transferred to the glass frit border lamination used to hermetically edge-seal the moisture sensitive OLED layer sandwiched between two impermeable, rigid substrates (often made of glass). If the OLED display is adhered directly to the device, then the frit border will be susceptible to de-lamination from pull forces when the device is dropped.